1. Field
The inventive concept relates to a method of programming a nonvolatile memory device and, more particularly, to a method of programming a NAND-type semiconductor flash memory device using a negative bias voltage.
2. Description of Related Art
Semiconductor memory devices may be largely classified into volatile memory devices and nonvolatile memory devices. A volatile memory device may store data as the logic state of a bistable flip-flop or as the charge stored in a capacitor. The volatile semiconductor memory device may only store or read data while power is supplied and will lose the stored data when the power is interrupted. The nonvolatile semiconductor memory device may be used to store programs and data in a wide range of applications, such as computers and communication devices.
A nonvolatile semiconductor memory device, such as an electrically erasable programmable read-only-memory (EEPROM), stores data even after power is interrupted. Since an EEPROM is electrically erasable and programmable, the EEPROM has been widely used as a system programming device or auxiliary memory device that needs to be continuously updated. A NAND-type flash memory device is generally more highly integrated (miniaturized) than a NOR-type flash memory device.
The NAND-type flash memory device includes a memory cell array to store data, and the memory cell array includes a plurality of cell strings (also called NAND strings). Each memory cell of the NAND-type flash memory device may perform erase and program operations using a Fowler-Nordheim (F-N) tunneling current.
In the program mode (the memory cell programming mode), a conventional NAND-type flash memory device may suffer from disturbance between a cell string coupled to a selected bit line and a cell string coupled to an unselected bit line.